JP2015112534A - Manufacturing method of electric heating type catalyst device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily manufacturing an electric heating type catalyst device at low cost.SOLUTION: The method for manufacturing an electric heating type catalyst device includes the steps of: temporarily fixing wires 32 to a masking jig 40 for forming a plurality of fixed beds 33 for fixing the wires 32 to a surface electrode 31; disposing the masking jig 40 having the temporarily fixed wires 32 on the outer peripheral surface of a carrier 20 such that the wires 32 are opposed to the surface electrode 31 installed on the carrier 20; flame spraying a flame spraying material to form the fixed beds 33 from a through portion 40a formed in the masking jig 40, so as to fix the wires 32 to the surface electrode 31 with the fixed beds 33; and releasing the temporal fixing of the wires 32 to the masking jig 40 for removal of the masking jig 40.

Description

  The present invention relates to a method for manufacturing an electrically heated catalyst device.

  In recent years, an electrically heated catalyst (EHC) attracts attention as an exhaust gas purification device that purifies exhaust gas discharged from an engine such as an automobile. In an electrically heated catalyst device, even when the exhaust gas temperature is low, such as immediately after engine startup, and the catalyst is difficult to activate, the catalyst is forcibly activated by energization heating to purify the exhaust gas. Efficiency can be increased.

  In the electrically heated catalyst device disclosed in Patent Document 1, a surface electrode extending in the axial direction of the carrier is provided on the outer peripheral surface of a cylindrical carrier having a honeycomb structure on which a catalyst such as platinum or palladium is supported. Is formed. Then, comb-like wiring is connected to the surface electrode by a fixed layer formed by thermal spraying, and current is supplied. When this current spreads in the direction of the carrier axis in the surface electrode, the whole carrier is heated by energization. As a result, the catalyst supported on the carrier is activated, and unburned HC (hydrocarbon), CO (carbon monoxide), NOx (nitrogen oxide), etc. in the exhaust gas passing through the carrier are purified by the catalytic reaction. The

JP 2013-136997 A

  The inventor has found the following problems in the method for producing an electrically heated catalyst device. For example, the electrically heated catalyst device is manufactured by the following method. First, as shown in FIG. 9, the wiring 102 is arranged at a predetermined position on the surface electrode 101 extending in the axial direction of the carrier 100, and the wiring 102 is pulled in the axial direction of the carrier 100 and the circumferential direction of the carrier 100. Then, the wiring 102 is fixed at a predetermined position on the surface electrode 101. Then, as shown in FIG. 10, the surface electrode 101 and the wiring 102 are connected by the fixed layer 103 by thermal spraying, and then the portion necessary only for pulling the wiring 102 (that is, to realize energization heating). In FIG. 10, the unnecessary portion 102a) is removed. 9 and 10, the axial direction of the carrier 100 is shown to coincide with the left-right direction of the paper.

  In such a manufacturing method, it is necessary to pull in order to fix the wiring in a predetermined position, or to remove an unnecessary portion after connecting the surface electrode and the wiring. Therefore, the manufacturing process is complicated. In addition, since the unnecessary portion is removed, the material yield is low, and the cost increases because the electroheating catalyst device is manufactured.

  This invention is made | formed in view of the above, Comprising: It aims at providing the method which can manufacture an electricity heating type catalyst apparatus easily cheaply.

A method for producing an electrically heated catalyst device according to an aspect of the present invention includes:
A carrier made of ceramics carrying a catalyst;
A pair of surface electrodes provided opposite to each other on the outer peripheral surface of the carrier;
Comb-like wiring for supplying power to the surface electrode from the outside;
A plurality of fixed layers for fixing the wiring to the surface electrode, and a method for producing an electrically heated catalyst device comprising:
Temporarily fixing the wiring to a masking jig for forming the fixing layer;
Placing the masking jig on which the wiring is temporarily fixed on the outer peripheral surface of the carrier, and facing the wiring and the surface electrode provided on the carrier;
Thermally spraying a thermal spray material forming the fixed layer from a through-hole formed in the masking jig, and fixing the wiring to the surface electrode by the fixed layer;
Releasing the temporary fixing to the masking jig in the wiring, and removing the masking jig;
Is provided.
Thereby, the position of the wiring can be fixed on the surface electrode using the masking jig. Further, the conventional part for fixing the wiring (the broken line part in FIG. 10) can be omitted. Therefore, the electrically heated catalyst device 10 can be manufactured inexpensively and easily.

In the above-described method for manufacturing an electrically heated catalyst device, it is preferable that the wiring is temporarily fixed to the masking jig by air attractive force or magnetic attractive force.
Thereby, wiring can be temporarily fixed to a masking jig easily.

In the above-described method for producing an electrically heated catalyst device, it is preferable that an accommodating portion for accommodating and positioning the wiring is formed on a surface of the masking jig that is disposed to face the carrier.
Thereby, the wiring can be temporarily fixed at a predetermined position simply by housing the wiring in the housing portion.

In the above-described method for producing an electrically heated catalyst device, it is preferable that a surface of the masking jig facing the carrier is curved so as to correspond to the outer peripheral surface of the carrier.
Thereby, the wiring can be bent so as to correspond to the outer peripheral surface of the carrier, and the wiring can be satisfactorily brought into contact with the surface electrode 31.

  According to the present invention, an electrically heated catalyst device can be manufactured inexpensively and easily.

1 is a perspective view showing an electrically heated catalyst device according to Embodiment 1. FIG. It is the top view which looked at the electrically heated catalyst apparatus which concerns on Embodiment 1 from right above the surface electrode. (A) is a top view which shows typically the masking jig used with the manufacturing method of the electroheating catalyst apparatus which concerns on Embodiment 1. FIG. (B) is a top view of (a). FIG. 4 is a schematic diagram showing a process of a method for manufacturing an electrically heated catalyst device according to Embodiment 1. FIG. 4 is a schematic diagram showing a process of a method for manufacturing an electrically heated catalyst device according to Embodiment 1. FIG. 4 is a schematic diagram showing a process of a method for manufacturing an electrically heated catalyst device according to Embodiment 1. In Embodiment 2, it is a perspective view which shows typically the state after manufacturing an electroheating catalyst apparatus using two masking jigs. (A) is the bottom view which shows the state which temporarily fixed the wiring to the masking jig in Embodiment 3. FIG. (B) is a top view of (a). It is a schematic diagram which shows the process of the manufacturing method of the conventional electrically heated catalyst apparatus. It is a schematic diagram which shows the process of the manufacturing method of the conventional electrically heated catalyst apparatus.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

(Embodiment 1)
First, the current heating type catalyst device manufactured by the method for manufacturing the current heating type catalyst device of the first embodiment will be described. FIG. 1 is a perspective view of an electrically heated catalyst device 10. FIG. 2 is a plan view of the electrically heated catalyst device 10 as viewed from directly above the surface electrode. 1 and 2, the axial direction of the carrier 20 is shown to coincide with the vertical direction of the page.

  The electrically heated catalyst device 10 is provided on an exhaust path of an automobile or the like, for example, and purifies exhaust gas discharged from the engine. As shown in FIGS. 1 and 2, the electrically heated catalyst device 10 includes a carrier 20, a surface electrode 31, a wiring 32, and a fixed layer 33.

  The carrier 20 is a porous member that supports a catalyst such as platinum or palladium. Further, since the carrier 20 itself is energized and heated, it is made of a ceramic having conductivity, specifically, for example, SiC (silicon carbide). The carrier 20 has a substantially cylindrical outer shape and has a honeycomb structure inside. As shown by arrows in FIG. 1, the exhaust gas passes through the inside of the carrier 20 in the axial direction of the carrier 20.

  The surface electrodes 31 are a pair of electrodes arranged to face each other on the outer peripheral surface of the carrier 20. The surface electrode 31 of the present embodiment has a rectangular planar shape and extends in the carrier axis direction. The surface electrode 31 is connected to a power source such as a battery via a wiring 32. Then, a current is supplied to the carrier 20 through the surface electrode 31 and heated by energization. One of the pair of surface electrodes 31 is a positive electrode and the other is a negative electrode. However, any surface electrode 31 may be a positive electrode or a negative electrode. That is, the direction of the current flowing through the carrier 20 is not limited.

  The wiring 32 formed in a comb-like shape is disposed on each of the pair of surface electrodes 31. The wiring 32 includes a first wiring 32a and a second wiring 32b. In the present embodiment, the first wiring 32a extends in a comb shape in the circumferential direction of the carrier, and the second wiring 32b extends in a comb shape in the direction of the carrier axis. Both the first wiring 32 a and the second wiring 32 b are in physical contact with the surface electrode 31 and are electrically connected. The first wiring 32a and the second wiring 32b are, for example, ribbon-like thin metal plates having a thickness of about 0.1 mm and a width of about 1 mm. The wiring 32 is preferably made of a heat-resistant (oxidation-resistant) alloy such as a stainless alloy, a Ni-based alloy, or a Co-based alloy, for example, in order to endure use at a high temperature of 800 ° C. or higher. In view of performance and cost such as electrical conductivity, heat resistance, oxidation resistance at high temperatures, and corrosion resistance in an exhaust gas atmosphere, stainless steel alloys are most preferable.

  The plurality of first wirings 32a are extended over the entire region where the surface electrode 31 is formed in the circumferential direction of the carrier. Furthermore, all the first wirings 32a are extended from one side of the formation region of the surface electrode 31, and are integrated at the protruding end. On the other hand, the plurality of first wirings 32a are arranged in parallel on the surface electrode 31 at substantially equal intervals along the carrier axis direction. Further, the first wiring 32 a is disposed only in the center part of the surface electrode 31 in the carrier axial direction. In the example of FIGS. 1 and 2, four first wirings 32 a are provided in the central portion of the carrier 20 on the surface electrode 31 in the axial direction. Here, the two outermost first wirings 32a are formed thicker than the other two first wirings 32a. As a matter of course, the number of the first wirings 32a is not limited to four, and is appropriately determined.

  The second wiring 32b extends continuously from the two outermost first wirings 32a to the end of the surface electrode 31 in the carrier axis direction. In the example of FIGS. 1 and 2, four second wirings 32b are extended from each of the two outermost first wirings 32a.

  The first wiring 32a and the second wiring 32b are fixed to the surface electrode 31 by a plurality of fixing layers 33 provided apart from each other. The fixed layer 33 is a button-shaped sprayed coating having a thickness of about 300 to 500 μm formed so as to cover the first wiring 32a or the second wiring 32b. The fixed layer 33 is in physical contact with and electrically connected to the first wiring 32 a or the second wiring 32 b and the surface electrode 31.

  Since the thermal spray coating constituting the surface electrode 31 and the fixed layer 33 is energized in the same manner as the wiring 32, it needs to be a metal base. The metal constituting the matrix of the thermal spray coating is a Ni-Cr alloy having excellent oxidation resistance at high temperatures in order to withstand use at high temperatures of 800 ° C. or higher (however, the Cr content is 20 to 60% by mass) ), MCrAlY alloy (where M is at least one of Fe, Co and Ni). Here, the NiCr alloy and MCrAlY alloy may contain other alloy elements. The thermal spray coating constituting the surface electrode 31 and the fixed layer 33 may be porous. By being porous, the function to relieve stress is enhanced.

  With the above configuration, in the electrically heated catalyst device 10, the carrier 20 is electrically heated between the pair of surface electrodes 31, and the catalyst supported on the carrier 20 is activated. Thereby, unburned HC (hydrocarbon), CO (carbon monoxide), NOx (nitrogen oxide) and the like in the exhaust gas passing through the carrier 20 are purified by the catalytic reaction.

  Next, a method for manufacturing the electrically heated catalyst device 10 according to Embodiment 1 will be described. Here, the masking jig 40 used in the method for manufacturing the electrically heated catalyst device 10 will be described. FIG. 3A is a plan view schematically showing the masking jig 40. FIG. 3B is a top view of FIG. 3A and 3B, the axial direction of the carrier 20 on which the masking jig 40 is arranged on the outer peripheral surface coincides with the vertical direction of the paper surface, and the masking jig 40 is shown based on this direction. Has been. 3A, the magnet 40b and the fitting hole 40c into which the magnet 40b is fitted are omitted so that the arrangement of the through holes 40a is clear.

  The masking jig 40 has a configuration in which the wiring 32 can be temporarily fixed and the fixing layer 33 can be sprayed by arranging the wiring 32 on the surface electrode 31 formed on the carrier 20 in a state where the wiring 32 is temporarily fixed. .

  As shown in FIG. 3A, the masking jig 40 of the present embodiment has a shape capable of covering at least the first wiring 32a and the second wiring 32b of the wiring 32. It is a piece of plate-like member formed in a rectangular shape when viewed from the thickness direction (that is, in plan view of the masking jig 40). Moreover, one surface in the thickness direction of the masking jig 40 is formed in a concave curved surface so as to correspond to the outer peripheral surface of the carrier 20 as shown in FIG.

  The masking jig 40 includes a through hole 40 a that penetrates in the thickness direction of the masking jig 40 so as to correspond to the arrangement of the fixed layer 33. The through hole 40 a has an inner peripheral shape substantially equal to the outer peripheral shape of the fixed layer 33. The masking jig 40 includes a magnet 40b so that the wiring 32 can be temporarily fixed (see FIG. 4 and the like). The magnet 40 b is fitted in a fitting hole 40 c formed in the masking jig 40.

  The fitting hole 40c is arranged so as not to interfere with the through hole 40a. For example, when the wiring 32 is temporarily fixed to the masking jig 40 so as to at least partially overlap with the through hole 40a when viewed from the thickness direction of the masking jig 40, it is fitted at a portion that does not interfere with the through hole 40a. The fitting hole 40c is arranged so that the magnet 40b fitted into the hole 40c overlaps the wiring 32. However, the arrangement of the magnet 40b is not particularly limited as long as the wiring 32 can be temporarily fixed. The fitting hole 40 c has an opening on the other surface in the thickness direction of the masking jig 40, and the magnet 40 b inserted from the opening does not directly contact the wiring 32.

  Here, on one surface in the thickness direction of the masking jig 40, as shown in FIG. 3A, an accommodation portion 40d for accommodating and positioning at least a part of the wiring 32 is formed. Is preferred. The accommodating part 40d arranges the wiring 32 at a position where at least a part of the through hole 40a and the wiring 32 overlap when the wiring 32 is accommodated in the accommodating part 40d when viewed from the thickness direction of the masking jig 40. The accommodating portion 40d of the present embodiment has an inner peripheral shape corresponding to a part of the outer peripheral shape of the wiring 32 on the other surface in the thickness direction of the masking jig 40, and a depth substantially equal to the thickness of the wiring 32. When the wiring 32 is accommodated in the recess, the wiring 32 is arranged at the above-described position. Thereby, the wiring 32 can be temporarily fixed at a predetermined position simply by housing the wiring 32 in the housing portion 40d. In addition, the wiring 32 can be brought into contact with the surface electrode 31. However, the shape of the accommodating portion 40d is not limited to the above, and for example, a configuration in which the wiring 32 accommodated in the recessed portion is partially fixed may be used.

  Using such a masking jig 40, the manufacturing method of the electrically heated catalyst device 10 is realized as follows. Here, FIGS. 4 to 6 are schematic views showing the respective steps of the method for manufacturing the electrically heated catalyst device 10, and the surface electrode 31, the wiring 32, and the masking jig 40 are shown as sectional views, and the carrier 20, the fixed layer 33 and the magnet 40b are shown as a front view. 4 to 6, the axial direction of the carrier 20 coincides with the left-right direction of the paper. Here, FIGS. 4 to 6 schematically show the method for manufacturing the electrically heated catalyst device 10, so the shapes of the elements shown in FIGS. 4 to 6 are the same as those shown in FIG. May not match the corresponding element.

  First, the surface electrode 31 is formed on the carrier 20. On the other hand, as shown in FIG. 4, the wiring 32 is accommodated and positioned in the accommodating portion 40d of the masking jig 40, and the wiring 32 is temporarily fixed to the masking jig 40 by the magnetic attraction force of the magnet 40b.

  Next, as shown in FIG. 5, the masking jig 40 is disposed on the outer peripheral surface of the carrier 20 with the surface of the masking jig 40 on which the wiring 32 is temporarily fixed facing the carrier 20, and the wiring 32 is placed on the surface. The electrode 31 is brought into contact. At this time, since the surface of the masking jig 40 on which the wiring 32 is temporarily fixed is formed so as to correspond to the outer peripheral surface of the carrier 20, the wiring 32 is bent so as to correspond to the outer peripheral surface of the carrier 20. The wiring 32 can be in good contact with the surface electrode 31.

  Next, in a state where the wiring 32 is fixed on the surface electrode 31 by the masking jig 40, the thermal spray material is sprayed from the through hole 40 a of the masking jig 40 to form the fixed layer 33, and the fixed layer 33 and the wiring 32 are The surface electrode 31 is connected.

  Finally, as shown in FIG. 6, when the temporary fixing of the wiring 32 to the masking jig 40 is released and only the masking jig 40 is removed, the manufacture of the electrically heated catalyst device 10 is completed. At this time, the magnetic attraction force of the magnet 40 b is preferably smaller than the bonding force by the fixed layer 33. Thereby, the wiring 32 does not follow the removal of the masking jig 40, and only the masking jig 40 can be removed favorably. Further, since the magnet 40b is arranged so as not to contact the wiring 32, it does not come out of the fitting hole 40c and remain on the wiring 32 side.

  As described above, the manufacturing method of the electrically heated catalyst device 10 according to the present embodiment can fix the position of the wiring 32 on the surface electrode 31 using the masking jig 40. The process of pulling and fixing the wiring 32 to fix the position can be omitted, and the current heating catalyst device 10 can be easily manufactured.

  In addition, since the wiring 32 can be fixed on the surface electrode 31 by using the masking jig 40, a conventional portion for fixing the wiring 32 (a broken line portion in FIG. 10) can be omitted. Therefore, it is possible to omit the step of removing an unnecessary portion of the wiring 32 after fixing the wiring 32 to the surface electrode 31 as in the prior art, and the current heating catalyst device 10 can be manufactured more easily.

  Further, since the portion for fixing the wiring 32 as in the prior art (the broken line portion in FIG. 10) can be omitted, the wiring 32 can be formed by omitting unnecessary portions in advance. Therefore, the material yield can be improved, and the electrically heated catalyst device 10 can be manufactured at a low cost.

(Embodiment 2)
Although the masking jig 40 of Embodiment 1 is comprised with one piece, you may comprise with a some division | segmentation piece. FIG. 7 is a perspective view schematically showing a state after the electrically heated catalyst device 10 is manufactured using the two masking jigs 41. In the following description, the same elements as those in the first embodiment will be described using the same reference numerals.

  In the present embodiment, the wiring 32 can be temporarily fixed by the two masking jigs 41. Specifically, the two masking jigs 41 have a basic configuration in which the masking jig 40 according to the first embodiment is divided into two at a substantially central position in the direction in which the first wiring 32a of the temporarily fixed wiring 32 extends. It is said.

  These two masking jigs 41 are preferably provided with a fitting structure on the surfaces facing each other. Thereby, when temporarily fixing the wiring 32, the positional deviation of the two masking jigs 41 can be suppressed.

  Incidentally, the masking jig 41 of the present embodiment includes the fixing portions 41a at both ends in the direction in which the second wiring 32b of the wiring 32 to be temporarily fixed extends. When fixing the position of the wiring 32 on the surface electrode 31, the masking jig 41 can be satisfactorily fixed by fixing the fixing portion 41a to a jig (not shown).

  Although the masking jig can be divided and implemented as described above, if it is configured with one piece as in the masking jig 40 of the first embodiment, it is easy to handle and occurs when a plurality of pieces are assembled and configured. The fixed layer 33 can be formed with high accuracy without any possible shift between the pieces.

(Embodiment 3)
In the first and second embodiments, the surface electrode 31 extends in the axial direction of the carrier 20, but the surface electrode 31 may extend in the circumferential direction of the carrier 20. Here, FIG. 8A shows the masking jig 42 used in the present embodiment, and is a bottom view showing a state where the wiring 32 is temporarily fixed to the masking jig 42. FIG. 8B is a top view of FIG. 8A and 8B, the axial direction of the carrier 20 on which the masking jig 42 is arranged on the outer peripheral surface coincides with the vertical direction of the paper surface, and the masking jig 42 is shown based on this direction. Has been. Incidentally, in the following description, the same reference numerals are used for the same elements as in the first embodiment.

  As shown in FIGS. 8A and 8B, the masking jig 42 includes a through hole 40a of the masking jig 40 according to the first embodiment, a housing portion 40d, and a fitting hole 40c of the magnet 40b in the plan view of the masking jig 42. Is substantially the same as the configuration in which the lens is rotated by approximately 90 °.

  In other words, the wiring 32 is accommodated in the accommodating portion 42d, and the masking jig 42 is arranged on the surface electrode 31 so that the concave curved surface arranged to face the carrier 20 in the masking jig 42 corresponds to the outer peripheral surface of the carrier 20. At this time, the accommodating portion 42d of the masking jig 42 is arranged so that the first wiring 32a is arranged in the axial direction of the carrier 20 and the second wiring 32b is arranged in the circumferential direction of the carrier 20. The through-holes are arranged so that the arrangement relationship between the wiring 32 accommodated in the accommodating portion 42d, the through-hole 42a, and the magnet satisfies the arrangement relationship between the wiring 32, the through-hole 40a, and the magnet 40b described in the first embodiment. A fitting hole into which 42a and a magnet are fitted is arranged. Incidentally, the masking jig 42 in the illustrated example has a shape that can cover the entire area of the wiring 32 when viewed from the thickness direction of the masking jig 42, but at least the first masking jig 40 is the same as the masking jig 40 of the first embodiment. Any shape that can cover the wiring 32a and the second wiring 32b may be used.

  Thus, in the same manner as the manufacturing method of the first embodiment, the first wiring 32a extends in the axial direction of the carrier 20 on the surface electrode 31 extended in the circumferential direction of the carrier 20, and the second wiring An electrically heated catalyst device in which 32b extends in the circumferential direction of the carrier 20 can be manufactured.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. For example, in the masking jig of the above embodiment, the wiring 32 is temporarily fixed by the magnetic attractive force of the magnet, but the wiring 32 may be temporarily fixed by the attractive force of air.

DESCRIPTION OF SYMBOLS 10 Electric heating type catalyst apparatus 20 Support | carrier 31 Surface electrode 32 Wiring, 32a 1st wiring, 32b 2nd wiring 33 Fixed layer 40 Masking jig, 40a Through-hole, 40b Magnet, 40c Fitting hole, 40d Housing part 41 Masking jig, 41a Fixed part 42 Masking jig, 42a Through hole, 42d Housing part 100 Carrier 101 Surface electrode 102 Wiring 103 Fixed layer

Claims (4)

A carrier made of ceramics carrying a catalyst;
A pair of surface electrodes provided opposite to each other on the outer peripheral surface of the carrier;
Comb-like wiring for supplying power to the surface electrode from the outside;
A plurality of fixed layers for fixing the wiring to the surface electrode, and a method for producing an electrically heated catalyst device comprising:
Temporarily fixing the wiring to a masking jig for forming the fixing layer;
Placing the masking jig on which the wiring is temporarily fixed on the outer peripheral surface of the carrier, and facing the wiring and the surface electrode provided on the carrier;
Thermally spraying a thermal spray material forming the fixed layer from a through-hole formed in the masking jig, and fixing the wiring to the surface electrode by the fixed layer;
Releasing the temporary fixing to the masking jig in the wiring, and removing the masking jig;
A method of manufacturing an electrically heated catalyst device comprising:   The method for manufacturing an electrically heated catalyst device according to claim 1, wherein the wiring is temporarily fixed to the masking jig by air suction force or magnetic attraction force.   3. The method for producing an electrically heated catalyst device according to claim 1, wherein a housing portion that accommodates and positions the wiring is formed on a surface of the masking jig that faces the carrier. 4.   4. The electrically heated catalyst device according to claim 1, wherein a surface of the masking jig facing the carrier is curved so as to correspond to an outer peripheral surface of the carrier. 5. Manufacturing method.

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